For example, Patent Document 1 discloses a reciprocating device (traveling vehicle system) wherein a movable body (traveling vehicle) receives electric power transmitted by a wireless power supply and is reciprocated by the electric power along a track (rail for the traveling). The reciprocating device is constructed so that the movable body is reciprocated along the track by having electric power supplied wirelessly from a pair of feeders (power transmission unit) arranged along the track to a power receiving unit (power receiving pickup) provided on the movable body.
Further, Patent Document 2 discloses a wireless power transmitting device that receives electric power transmitted by a wireless power supply through a resonance phenomenon and that charges a battery of a movable body (electric car) with the electric power. The wireless electric power transmitting device is constructed so that the transmission efficiency of electric power is improved by making the resonance frequency of resonance coils and the frequency of an alternating-current power coincide with each other.